Signaling system



Feb. 8,1927. 1,616;6o7

A. A. CLOKEY SIGNALING SYSTEM Filed Dec'. 15, 1923 l M .I-III/ @ma n Patented Feb. 8, 1927.

rUNITED STATES PATENT OFFISE.

ALLISQN A. (L-GREY, OF RUTEERFRD, NEVI JERSEY, ASSEGEOR TG VJESTLERN ELEC- TRIC COMPANY, INCORPORATED, CIF NEW YORK, N. Y., .A CORPORATION OF NEVI YORK.

SIGNALTNG SYSTEM.

Application filed December 15, 1923.

This invention relates to signaling systems and particularly to the apparatus and cir- `cuits employed for transmitting signaling impulses which are controlled by suitable perforated message tape, and for equalizing the length of such impulses transmitted to the line.

The Wheatstone type of transmitter as commonly used for submarine cable transmission is limited in its speed of satisfactory operation due to the inertia of its reciprocating contact arms and the unavoidable vibration of its moving parts. Since loaded submarine telegraph cables are capable of considerably higher speeds of transmission, it is of importance to devise a more suitable type of transmitter which will function satisfactorily at speeds of the order of those at which a well designed loaded cable is capable of transmitting.

lt is therefore an object of the present invention to improve the construction of an automatic telegraph transmitter so that it will be capable of operating at a high rate l of speed to cause the rapid breaking and closing of firm contacts. Tt is a further object of the invention to produce a transmitter of this kind that will be simple and compact, free from liability of derangeinent and relatively inexpensive in construction.

A further object of the invention 1s to make it possible to control the time interval during which each signal impulse is impressed upon the line, thus equalizing the 35 impulses with respect to each other if desired and controlling the length of signal.

To accomplish these objects and in accordance with a feature of the invention, the movable contact members of the transmitter are operated by changes in pressure which areunder the direct control of the perforated message tape.

ln accordance with another feature of the invention7 a commutating device cooperates with the contact members to regulate the portion of the signal impulso which is impressed upon the line.

These and other features of the invention may be more clearly understood by reference to the accompanying drawing in which Fig. 1 shows schematically a transmitter en'ibodying the features of the invention and illustrates the method employed for controlling the length of the signaling impulses, and Fig. 2 is a sectional view showing Serial No. 680,8 15.

the means by which the perforated message tape causes variation in the pressure leX- erted on the diaphragms.

Referring to these drawings, the transmitting mechanism comprises a suitable reservoir 5 upon which are mounted supporting members 6 and 7 provided with shallow cylindrical air chambersS and 9 which are enclosed respectively by means of flexible diaphragms 10 and 11. rlie diaphragm 10 carries a contact member 12 which is adapted to engage a contact screw 13 adjustably mounted on the plate lil and insulated from the supporting member G by means of suitable insulators 15, 15. In a` similar manner the diaphragm 11 carries a contact member 16 arranged to engage contact screw 17 adjustably mounted on plate 13 and insulated from support 7 by insulating members 15, 15. The air chambers 8 and 9 are connected with the reservoir 5 by means of passages 2O and 21 which are provided respectively with adjustable valves 22, 23 which permit regulation of the frictional resistance offered to the passage of air therethrough. The support 6 is also provided with an air passage 26 communicating with the chamber 8 and extending by means of suitable means such as a pipe 27 to a similar passage 28 in the tape supporting block 29. Likewise, the support 7 is provided with an air passage 30 connecting by means of pipe 31 to a second air passage 32 in tape block 29. (For the sake of clearness, the tape block is not shown in Fig. 1, but is shown in section in Fig. 2.) The passages 31 and 32 have inwardly extending horizontal porti-ons which are covered by the platen 33 over which the message tape 34 is drawn. This platen is provided with two perforations in transverse alignment with respect to the tape and so positioned as to be in alignment with the code perforations in the tape. The perforations in the platen may be of any desired shape and are so positioned that a perforation in the tape corresponding to a dot will uncover the passage way 32 and a perforation in the tape corresponding to a dash will uncover the passage 28.

The tape feeding mechanism comprises a star wheel 35 mounted on the shaft 36 which is positively driven by the motor 37. The projections on the star wheel ext-end through a suitable slot in the platen 33 and engage perforations provided in the center line of "5T Vare fixed in posi ion with respect the tape. rlfhe roller 38 which serves to hold the tape firm-ly against the platen is provided with a center groove to permit free movement ont' the star wheel and with two outer grooves in alignment with the perterations in the platen to permit tree escape of air when the peritorations in the platen and the message tape are in alignment. A pair ot springs not shown in the drawing keep the roller 38 pressed against the tape with the desired pressure.

The reservoir 5 is maintained at the dcsired pressure by means of the compressor 4() connected to the drivin;l motor l1 and a pressure regulating' valve Lt2 wnich maintains the pressure at a predetermined value. It has been found that a pressure et the order ot three inches et mercury is suflicient to permit satisfactory movement. ot the diaphragms.

The application et' this transmitter to telegraph transmitting' systems diti1 ers somewhat from standard practice'due to the fact that the contacts open instead o't close in rc` spense to a perforation in the tape. The contacts 12 and 16 are connected together through `the diaphragme 10 and 11, and supports 6 and 7 and are then grounded. rllhe contact screw 13 is connected to the poitive terminal orn battery 415 and contact screw 17 is connec ed to the negative terminal ot battery 16. These batteries are connected in series, balanced resistances 417 and 18 being' provided as shown to limit the current drain on the batteries when both contact screws `are in contact with their respective 'diaphragm contacts at the same time. rllhe junction o't resistances 47 and 118 is connected to ground through resistance 19, the purpose ot which will be explained hereinafter. To preveru: excessive sparking on the contacts, resistance is connected in series with condenser 51 across the contacts 12, 12E and in series with condenser 52 across contacts 16 and 17.

In order to equalize the length ot signal impulses land to provide a desired degree ot curb-ingr, a curbing device is preterab'ly provided comprising a comniutator mounted on the shatft 3G 'and hating; an even nuinher ot segments equal Ato the number et projections 'on the star wheel 35 which 'tecds the ineasaggje tape. Alternate segments are connecteditoeether :is are also Athe i'utf'rnie-fl:itc segments TT. `irush connected to ygroui-id Ithrough insistance 5G, brush 57 is connected te the u ,Minded terminal o1' resistance ft2) and br sh 53 is connected directly on the line or cable 59. Brushes and I to each 'other so that a'tthe instant brush is just passingupen a segment S, brush :37 will be just passing` upon a segment T. Brush 58 is "mounted upon an adjustable arm SO which is 'capable offbeing rocked so that the brush positive terminal et battery 'S and "ll, T

moves over the arc of a. circle equal to the length ot one ot the segments. An indicator 61 is provided to indicate the setting of 'the brush and therefore the degree ot curbing.

The operation o't the device is as follows: Assuming that. contacts 12 and 16 are in engagement with their respective contact screws 13 and 17 and resistances 11T and 48 are equal, the tendency tor current to flow in the circuit comprising battery 115, contact screw 13, contact 12, resistance 9, and resistance e? will be equal but opposite lin direction to the tendency vtor current to flow in the circuit comprising battery 46, resistance L18, resistance 119, contact 1G, contact screw 17. Therefore, no current will actually tiow through resistance 119 and ythere will be no difference ot 'potential existing; between the cable 59 `and groun l. Should the contact 12 be out ot engagement with the contact screw 13 (as shown on the drawin response to a dash perforation in the transruittine` tape, current will then flow from the positive terminal of be. tery do, through resistance 4S, resistance 49. contact 16 and contact screw ls'and bacli to tl e negative terminal ot battery 116. The difference in potential existing' lacross resistance t9 due to this current will be applied through brush 57, segments TT and brush 58 to the cable 59. lhen a contact is again established between contact 12 and contact screw 13, a cir- V15) to `zero asnfl tern'iinating' the.transmission ln a similar manner, in al inV the perforated oit that impulse. response to 'a detrtape, the pressure of Lne inner side et diaphragm 11 is reduced `thus causing' contact 1G to break engagement with co l`ct sciiew 17 .in which case ci: rent flows 'trom the Vi thv-rough cow tact screw 1S, Contact 12, resiutancf.: and resistance k(t7 back lo 'the negative terminal et battery A di'tl'lcrcnce in potentialv vopposite in sign to that just mentioned new exists across the resistance il-9 and is applied to the cable 59 bj.' nieuus ot brush 57, sehe'- inents T. T und brush The. connnutator comprising segments S, y and lufuslies .Vi-Fi. 5T and 58 is provided tor equalizing' the lcugrth ol the current limpulses impressed upon the line or changing the amount el signal mu'bing'. stated ,fi-beve, brushes and 5T are tired in position with 'report to @zich othe' so that 'brush will alrays be just passing upon onexoi1 the S segments at the instant brush '57 is just upon one et vthe 'E segr ments. It' brush T58 is so positioned that it will also lee just passing upon one ot 'the T :segments yat the inst-ant .brush is passing upon the T segment, then the cable Will be connected to the `transmitting circuit during ,the entire time represented by the rotation of the c i mmutator, through a distance equal to the length ofyone segment, and during this time the ground through resistance 56 and brush will not be el lstrically connected to either the. cable 59 or the transmitting network. Thus the signal transmitted to the cable is of the full length produced by the closure or openingI of either the contacts 12-13 or lil- 17. New if the position of brush 58 is shifted by the rotation or" lever 60 so that itis passing upon one of the S segments at the time brush 57 is just passing upon segment T, then the cable will be connected to ground through brush 58, segments S, S, brush 55 and resistance 56, and the transmitting network will not be connected to either. This represents the condition for curbingl or zero marking and it is obvious that intermediate positions of the brush 58, will result in applying an amount of curbing to the transmitted signal which is proportional to the displacement of brush 58 from its first described position at the beginning of segment T. One of the advantages of employing this method of altering the curbing interval is that the adjustment can be made While the transmitter is in operation and the adjusting means can be calibrated, if desired.` so that the exact amount of curbing applied may be read from an indicating dial Without the necessity of measurement by the longer methods involving the use of an oscillograph or other recording or indicating device.

In the transmitter as described, a compresser is employed to maintain a definite pressure in the reservoir 5, but it is obvious that this compressor might be replaced by a vacuum pump which will maintain a partial va-cuum in the reservoir 5. ln this case the tlexure of the diaphragms due to a code perforation in the tape passing over the platen would be in the opposite direction and would Cause a closure of a contact rather than an opening.

It is preferred to employ air to operate the transmitter but other gases or even liquids may be used.

The invention claimed is:

l. ln a telegraph system employing a perforated message tape, a diaphragm closing an air chamber, a pair of contact members controlled by said diaphragm, means for normally maintaining the air in said chamber under pressure, and a platen having pertorations therein in alignment with the perforations in the message tape and cooperating therewith to lower the pressure in said air chamber thereby controlling the movement of the diaphragm.

2. Ina telegraph system employing a perlforated message tape, a diaphragm closing an air chamber, a reservoir connected therewith by means of a passage oilering a constant frictional resistance to the iiow of air therethrough, a pair of normally engaged contact members controlled by said diaphragm, means for increasing tho pressure in said air chamber, a pressure regulating valve for maintaining a uniform pressure in said reservoir, and means controlled by the perforations in the message tape for varying the pressure in said air chamber by releasing air therefrom thereby causing the separation of said contact members.

8. ln a telegraph system employing a perforated message tape, a diaphragm closing an air chamber, a pair of contact members controlled by said diaphragm, means for forcing air into said air chamber through a passage affording a constant frictional resistance to the iioiv of air therethrough, means for regulating said frictional resistance, and means controlled by the perforations in the message tape for releasing air trom and thus varying the pressure in said air chamber thereby causing the operation of said Contact members.

In a telegraph system employing a perforated message tape, a resistance member and pneumatic means under the control of the perforations in the message tape for impressing voltages of either polarity across said resistance.

5. In a telegraph systeml employing a perforated message tape, a resistance, a diaphragm under the control of perforations in the message tape, a pair of Contact members operated by said diaphragm to transmit current impulses through said resistance, a second diaphragm under the control of other perforations in the message tape, and a pair of contact members operated by said second diaphragm to transmit current impulses through said resistance in an opposite direction.

0. In a telegraph system, the combination of a pneumatic transmitter with a commutating device for equalizing the length of the current impulses transmitted thereby.

7. In a telegraph system employing a perforated message tape, the combination of a pneumatic transmitter with a commutating device positively driven with respect to said message tape for controlling the length of current impulses impressed upon the line.

8. In a telegraph system, a resistance, an automatic transmitter for impressing current impulses across said resistance, and a commutating device positively driven with respect to the movement of the message tape for curbing and transmittingsaid impulses to the line.

9. In a telegraph system employing` a perforated message tape, an automatic transmitter, a star Wheel for causing movement ot' the message tape and a curbing device comprising an even number of segments corresponding to the number of projections on the star Wheel, alternate segments being connected together electrically, alternate intermediate segments being connected together electrically, a pair of brushes mounted in lined relation to each other, one of said brushes being grounded, the other o'j said brushes being connected to the transmitter, and an adjustable brush connected to the line over which impulses are to be transmitted.

l0. ln a telegraph system employing a message tape, an automatic transmitter tor transmitting current impulses, and a Commutating device for equalizing the length. oit said impulses, said device being adjustable during operation to control the length of current impulses transmitted to the line.

1l. In a telegraph system employing a message tape, an automatic transmitter tor transmitting current impulses and a curbing device for regulating the length of such im pulses as impressed upon the line, said curbing device being adjustable during operation to control the length ot' signals transmitted to the line :trom the full length ot the impulses obtained rom the transmitter to zero length.

12. ln a telegraph system employing la message tape, an automatic transmitter for transmitting current impulses, a commutating device adjustable during operation for controlling the length of such impulses transmitted to the line, and means for indicating the amount ot curbing applied to the signals.

13. A high'speed telegraphic transmitter comprising two fluid conduits, means for moving a perforated message tape With respect to said conduits so that the perforations representingdots permit fluid from one ot said conduits to pass therethrough and the periorations representing` dashes permit tluid trom the other conduit to pass therethrough, and means cooperating with the tiuid passed ,through the per'lorations to set up electric currents in one direction or the other dep-ending upon Whether the fluid Was passed by a dot perforation or a dash pe rtoration.

i4. In a pneumatic transmitter, a gas chamber, the pressure in Which is controlled by perforated tape, and means operated in correspondence with the signals for compensating in part, at least. for variations of pressure in said chamber due to unequal distribution of the pert'olations.

ln Witness whereof, l hereunto subscribe my name this 7th day of December, A. D. 1923.

ALLISON A. CLOKEY. 

